How long to feed medicated feed to 12 week old chickens

[jburts]

how long should I feed medicated feed to my 12 almost 13 week old chickens? last time I kept the new ones on medicated for 9 weeks, and then switched them, this time I still have them on medicated at 12 weeks, they just started getting outside in the last two weeks,
in a couple of weeks or so they will be out with the older ones for a trial run, they are not integrated yet in coup, with older ones.
thanks,

 

[jburts]

my picture of my 6 year old easter egger still laying eggs, and not attacking the kennel anymore when the new ones are outside in their kennel, the 12 week ones get out in the grass and dirt, without the big ones out, then I put them back in kennel while the adult chickens are out so they get used to them before the trial run of letting them loose together.

 

[chickens really]

Switch them to a non layer feed..Grower unmediated.

 

[GC-Raptor]

I kept my day old chicks on medicated (Amprolium) Start & Grow feed for 16 weeks before transitioning to a layers feed over a 2 week period.
I have since read that Amprolium is effective up to 10 weeks.
My next batch of chicks will get changed to a non-medicated Start & Grow when the medicated feed runs out after 10 weeks. GC

 

[jburts]

ok thanks just lost my 6 yr old hen this week, she got sick but nothing that can spread, she started having digestive issues, and it got worse, she stoppped eating and I think she developed sour crop but nothing helped, she has never had issues or been sick, and we lost our five yr old last year same thing, never had the young ones get it, so maybe old age and digestive system slowing down or failing, don't know, anyway other chickens are doing great, and need to intergrate new ones here soon, they are in back yard together for the last two weeks, they are now 15 weeks old. so I'm finishing up the medicated feed, and switch them to non medicated feed, until they start laying eggs, also what do you all do for crop maintaince? I heard of putting apple cider vinegar in with water and I put probiotics in there water from time to time, any suggestions?